<div style="text-align: center;">
    用户名:<input type="text" data-bind="value: username"/><br>
    密&nbsp;&nbsp;&nbsp;码:<input type="password" data-bind="value: password"/><br>

    <select style="width: 100px;text-align: center" data-bind="options: identityList,
                    optionsText: 'identityName',
                    optionsValue:'identityId',
                    value: selectedIdentity,event:{change: selectChange}">
    </select>
    <input type="button" data-bind="value: submitBtn,click: function(data, event){userLogin(data, $root, event);}"/>
</div>
